| /* GNU/Linux/x86-64 specific low level interface, for the in-process |
| agent library for GDB. |
| |
| Copyright (C) 2010-2021 Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| #include "server.h" |
| #include <sys/mman.h> |
| #include "tracepoint.h" |
| #include "linux-x86-tdesc.h" |
| #include "gdbsupport/x86-xstate.h" |
| |
| /* Defined in auto-generated file amd64-linux.c. */ |
| void init_registers_amd64_linux (void); |
| extern const struct target_desc *tdesc_amd64_linux; |
| |
| /* fast tracepoints collect registers. */ |
| |
| #define FT_CR_RIP 0 |
| #define FT_CR_EFLAGS 1 |
| #define FT_CR_R8 2 |
| #define FT_CR_R9 3 |
| #define FT_CR_R10 4 |
| #define FT_CR_R11 5 |
| #define FT_CR_R12 6 |
| #define FT_CR_R13 7 |
| #define FT_CR_R14 8 |
| #define FT_CR_R15 9 |
| #define FT_CR_RAX 10 |
| #define FT_CR_RBX 11 |
| #define FT_CR_RCX 12 |
| #define FT_CR_RDX 13 |
| #define FT_CR_RSI 14 |
| #define FT_CR_RDI 15 |
| #define FT_CR_RBP 16 |
| #define FT_CR_RSP 17 |
| |
| static const int x86_64_ft_collect_regmap[] = { |
| FT_CR_RAX * 8, FT_CR_RBX * 8, FT_CR_RCX * 8, FT_CR_RDX * 8, |
| FT_CR_RSI * 8, FT_CR_RDI * 8, FT_CR_RBP * 8, FT_CR_RSP * 8, |
| FT_CR_R8 * 8, FT_CR_R9 * 8, FT_CR_R10 * 8, FT_CR_R11 * 8, |
| FT_CR_R12 * 8, FT_CR_R13 * 8, FT_CR_R14 * 8, FT_CR_R15 * 8, |
| FT_CR_RIP * 8, FT_CR_EFLAGS * 8 |
| }; |
| |
| #define X86_64_NUM_FT_COLLECT_GREGS \ |
| (sizeof (x86_64_ft_collect_regmap) / sizeof(x86_64_ft_collect_regmap[0])) |
| |
| void |
| supply_fast_tracepoint_registers (struct regcache *regcache, |
| const unsigned char *buf) |
| { |
| int i; |
| |
| for (i = 0; i < X86_64_NUM_FT_COLLECT_GREGS; i++) |
| supply_register (regcache, i, |
| ((char *) buf) + x86_64_ft_collect_regmap[i]); |
| } |
| |
| ULONGEST |
| get_raw_reg (const unsigned char *raw_regs, int regnum) |
| { |
| if (regnum >= X86_64_NUM_FT_COLLECT_GREGS) |
| return 0; |
| |
| return *(ULONGEST *) (raw_regs + x86_64_ft_collect_regmap[regnum]); |
| } |
| |
| #ifdef HAVE_UST |
| |
| #include <ust/processor.h> |
| |
| /* "struct registers" is the UST object type holding the registers at |
| the time of the static tracepoint marker call. This doesn't |
| contain RIP, but we know what it must have been (the marker |
| address). */ |
| |
| #define ST_REGENTRY(REG) \ |
| { \ |
| offsetof (struct registers, REG), \ |
| sizeof (((struct registers *) NULL)->REG) \ |
| } |
| |
| static struct |
| { |
| int offset; |
| int size; |
| } x86_64_st_collect_regmap[] = |
| { |
| ST_REGENTRY(rax), |
| ST_REGENTRY(rbx), |
| ST_REGENTRY(rcx), |
| ST_REGENTRY(rdx), |
| ST_REGENTRY(rsi), |
| ST_REGENTRY(rdi), |
| ST_REGENTRY(rbp), |
| ST_REGENTRY(rsp), |
| ST_REGENTRY(r8), |
| ST_REGENTRY(r9), |
| ST_REGENTRY(r10), |
| ST_REGENTRY(r11), |
| ST_REGENTRY(r12), |
| ST_REGENTRY(r13), |
| ST_REGENTRY(r14), |
| ST_REGENTRY(r15), |
| { -1, 0 }, |
| ST_REGENTRY(rflags), |
| ST_REGENTRY(cs), |
| ST_REGENTRY(ss), |
| }; |
| |
| #define X86_64_NUM_ST_COLLECT_GREGS \ |
| (sizeof (x86_64_st_collect_regmap) / sizeof (x86_64_st_collect_regmap[0])) |
| |
| /* GDB's RIP register number. */ |
| #define AMD64_RIP_REGNUM 16 |
| |
| void |
| supply_static_tracepoint_registers (struct regcache *regcache, |
| const unsigned char *buf, |
| CORE_ADDR pc) |
| { |
| int i; |
| unsigned long newpc = pc; |
| |
| supply_register (regcache, AMD64_RIP_REGNUM, &newpc); |
| |
| for (i = 0; i < X86_64_NUM_ST_COLLECT_GREGS; i++) |
| if (x86_64_st_collect_regmap[i].offset != -1) |
| { |
| switch (x86_64_st_collect_regmap[i].size) |
| { |
| case 8: |
| supply_register (regcache, i, |
| ((char *) buf) |
| + x86_64_st_collect_regmap[i].offset); |
| break; |
| case 2: |
| { |
| unsigned long reg |
| = * (short *) (((char *) buf) |
| + x86_64_st_collect_regmap[i].offset); |
| reg &= 0xffff; |
| supply_register (regcache, i, ®); |
| } |
| break; |
| default: |
| internal_error (__FILE__, __LINE__, |
| "unhandled register size: %d", |
| x86_64_st_collect_regmap[i].size); |
| break; |
| } |
| } |
| } |
| |
| #endif /* HAVE_UST */ |
| |
| #if !defined __ILP32__ |
| /* Map the tdesc index to xcr0 mask. */ |
| static uint64_t idx2mask[X86_TDESC_LAST] = { |
| X86_XSTATE_X87_MASK, |
| X86_XSTATE_SSE_MASK, |
| X86_XSTATE_AVX_MASK, |
| X86_XSTATE_MPX_MASK, |
| X86_XSTATE_AVX_MPX_MASK, |
| X86_XSTATE_AVX_AVX512_MASK, |
| X86_XSTATE_AVX_MPX_AVX512_PKU_MASK, |
| }; |
| #endif |
| |
| /* Return target_desc to use for IPA, given the tdesc index passed by |
| gdbserver. */ |
| |
| const struct target_desc * |
| get_ipa_tdesc (int idx) |
| { |
| if (idx >= X86_TDESC_LAST) |
| { |
| internal_error (__FILE__, __LINE__, |
| "unknown ipa tdesc index: %d", idx); |
| } |
| |
| #if defined __ILP32__ |
| switch (idx) |
| { |
| case X86_TDESC_SSE: |
| return amd64_linux_read_description (X86_XSTATE_SSE_MASK, true); |
| case X86_TDESC_AVX: |
| return amd64_linux_read_description (X86_XSTATE_AVX_MASK, true); |
| case X86_TDESC_AVX_AVX512: |
| return amd64_linux_read_description (X86_XSTATE_AVX_AVX512_MASK, true); |
| default: |
| break; |
| } |
| #else |
| return amd64_linux_read_description (idx2mask[idx], false); |
| #endif |
| |
| internal_error (__FILE__, __LINE__, |
| "unknown ipa tdesc index: %d", idx); |
| } |
| |
| /* Allocate buffer for the jump pads. The branch instruction has a |
| reach of +/- 31-bit, and the executable is loaded at low addresses. |
| |
| 64-bit: Use MAP_32BIT to allocate in the first 2GB. Shared |
| libraries, being allocated at the top, are unfortunately out of |
| luck. |
| |
| x32: Since MAP_32BIT is 64-bit only, do the placement manually. |
| Try allocating at '0x80000000 - SIZE' initially, decreasing until |
| we hit a free area. This ensures the executable is fully covered, |
| and is as close as possible to the shared libraries, which are |
| usually mapped at the top of the first 4GB of the address space. |
| */ |
| |
| void * |
| alloc_jump_pad_buffer (size_t size) |
| { |
| #if __ILP32__ |
| uintptr_t addr; |
| int pagesize; |
| |
| pagesize = sysconf (_SC_PAGE_SIZE); |
| if (pagesize == -1) |
| perror_with_name ("sysconf"); |
| |
| addr = 0x80000000 - size; |
| |
| /* size should already be page-aligned, but this can't hurt. */ |
| addr &= ~(pagesize - 1); |
| |
| /* Search for a free area. If we hit 0, we're out of luck. */ |
| for (; addr; addr -= pagesize) |
| { |
| void *res; |
| |
| /* No MAP_FIXED - we don't want to zap someone's mapping. */ |
| res = mmap ((void *) addr, size, |
| PROT_READ | PROT_WRITE | PROT_EXEC, |
| MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); |
| |
| /* If we got what we wanted, return. */ |
| if ((uintptr_t) res == addr) |
| return res; |
| |
| /* If we got a mapping, but at a wrong address, undo it. */ |
| if (res != MAP_FAILED) |
| munmap (res, size); |
| } |
| |
| return NULL; |
| #else |
| void *res = mmap (NULL, size, PROT_READ | PROT_WRITE | PROT_EXEC, |
| MAP_PRIVATE | MAP_ANONYMOUS | MAP_32BIT, -1, 0); |
| |
| if (res == MAP_FAILED) |
| return NULL; |
| |
| return res; |
| #endif |
| } |
| |
| void |
| initialize_low_tracepoint (void) |
| { |
| #if defined __ILP32__ |
| amd64_linux_read_description (X86_XSTATE_SSE_MASK, true); |
| amd64_linux_read_description (X86_XSTATE_AVX_MASK, true); |
| amd64_linux_read_description (X86_XSTATE_AVX_AVX512_MASK, true); |
| #else |
| for (auto i = 0; i < X86_TDESC_LAST; i++) |
| amd64_linux_read_description (idx2mask[i], false); |
| #endif |
| } |